Binarization algorithm not smart enough

[lberki]

It compares every pixel to its local neighborhood of a constant size. Thus, if the module size is larger than that, it will fail (because a module is full-black or full-white).

Was surprising to learn that a perfectly aligned, crisp, black-and-white QR code image cannot be scanned for this reason.

One solution would be to run binarize after the finder patterns were found and use only the pixels in the run being checked for the black/and white decision during pattern finding. However, it would make things even slower.